Pompey are closing in on adding a League One right-back to their squad.
And the Fratton Park future of Ben Davies is in doubt with still no agreement on a new deal.
Paul Cook has already eyed a return for Kieron Freeman, who was made available for transfer by Sheffield United last month.
However, it is understood he has now turned his attention to a free agent from a fellow League One outfit.
The Blues face competition for the signature of the attacking right-back, who featured regularly for his club last term.
Yet they are hoping the lure of the south coast can prove persuasive and help clinch a fourth recruit of the close season.
Cook also remains interested in retaining Davies, who enjoyed such an outstanding Fratton Park campaign last term.
The veteran player is eager to stay, however both parties continue to struggle to reach agreement.
Contract talks were initially opened at the end of last year, but remain unresolved, much to the concern of many Pompey followers.
Davies is a hugely popular figure among the Fratton faithful and runner-up in The News/Sports Mail Player of the Season vote.
As it stands, first-year professional Calvin Davies is the only right-back in the Blues’ first-team squad. The 18-year-old is also returning from injury at present.
That is in contrast to left-back, where Brandon Haunstrup is challenging Enda Stevens for the role.
Pompey have so far signed Danny Rose and Carl Baker during the close season, while Matt Clarke has turned his stay into a permanent one.
Danny Hollands is also negotiating a new deal.